HighlightsAn electrophysiological study of tremor can be helpful for the diagnosis.A study of hand tremor can be done with surface EMG and an accelerometer.Analysis in the frequency domain allows separating the different tremor components.Coherence analysis shows whether there are one or more oscillators.

Cervical angina has been widely reported as a cause of chest pain but remains underrecognized. This series demonstrates the varied clinical presentation of patients with cervical angina, the delay in diagnosis, and the extensive cardiac examinations patients with this condition typically undergo prior to a definitive diagnosis. Recognition of this condition in patients with acute chest pain requires a high index of suspicion and an awareness of the common presenting features and clinical findings of cervical angina.

Humans have a distinguishing ability for fine motor control that is subserved by a highly evolved cortico-motor neuronal network. The acquisition of a particular motor skill involves a long series of practice movements, trial and error, adjustment and refinement. At the cortical level, this acquisition begins in the parieto-temporal sensory regions and is subsequently consolidated and stratified in the premotor-motor cortex. Task-specific dystonia can be viewed as a corruption or loss of motor control confined to a single motor skill. Using a multimodal experimental approach combining neuroimaging and non-invasive brain stimulation, we explored interactions between the principal nodes of the fine motor control network in patients with writer’s cramp and healthy matched controls. Patients and healthy volunteers underwent clinical assessment, diffusion-weighted MRI for tractography, and functional MRI during a finger tapping task. Activation maps from the task-functional MRI scans were used for target selection and neuro-navigation of the transcranial magnetic stimulation. Single- and double-pulse TMS evaluation included measurement of the input-output recruitment curve, cortical silent period, and amplitude of the motor evoked potentials conditioned by cortico-cortical interactions between premotor ventral (PMv)-motor cortex (M1), anterior inferior parietal lobule (aIPL)-M1, and dorsal inferior parietal lobule (dIPL)-M1 before and after inducing a long term depression-like plastic change to dIPL node with continuous theta-burst transcranial magnetic stimulation in a randomized, sham-controlled design. Baseline dIPL-M1 and aIPL-M1 cortico-cortical interactions were facilitatory and inhibitory, respectively, in healthy volunteers, whereas the interactions were converse and significantly different in writer’s cramp. Baseline PMv-M1 interactions were inhibitory and similar between the groups. The dIPL-PMv resting state functional connectivity was increased in patients compared to controls, but no differences in structural connectivity between the nodes were observed. Cortical silent period was significantly prolonged in writer’s cramp. Making a long term depression-like plastic change to dIPL node transformed the aIPL-M1 interaction to inhibitory (similar to healthy volunteers) and cancelled the PMv-M1 inhibition only in the writer’s cramp group. These findings suggest that the parietal multimodal sensory association region could have an aberrant downstream influence on the fine motor control network in writer’s cramp, which could be artificially restored to its normal function.

BackgroundBackground: Many different movement disorders have similar "jerk-like" phenomenology and can be misconstrued as myoclonus. Different types of myoclonus also share similar phenomenological characteristics that can be difficult to distinguish solely based on clinical exam. However, they have distinctive physiologic characteristics that can help refine categorization of jerk-like movements. Objectives Objectives: In this review, we briefly summarize the clinical, physiologic, and pathophysiologic characteristics of different types of myoclonus. The methodology and technical considerations for the electrophysiologic assessment of jerk-like movements are reviewed. A simplistic pragmatic approach for the classification of myoclonus and other jerk-like movements based on objective electrophysiologic characteristics is proposed. Conclusions Conclusions: Clinical neurophysiology is an underutilized tool in the diagnosis and treatment of movement disorders. Various jerk-like movements have distinguishing physiologic characteristics, differentiated in the milliseconds range, which is beyond human capacity. We argue that the categorization of movement disorders as myoclonus can be refined based on objective physiology that can have important prognostic and therapeutic implications.The clinical approach to the diagnosis of movement disorders begins with the initial clinical classification of the movements observed based on phenomenology into a discrete number of categories: tremor, myoclonus, chorea, ballism, athetosis, dystonia, spasms, tics, motor stereotypies, and functional. The correct categorization of the movement disorder, or syndrome identification, is a critical first step in arriving at the correct etiological diagnosis. In this article, we address the methodology for improving the clinical characterization of myoclonus, including the pitfalls and challenges. Myoclonus is defined as a syndrome clinically characterized by sudden, brief "jerklike" movements. It can be further classified either as positive, when associated with an active muscle contraction, or negative, when associated with a brief pause in ongoing muscle contraction. [1][2][3] Should any jerk-like movement be called "myoclonus"? Tic disorders, chorea, ballism, dystonia, and functional movements can all have some jerk-like phenomenology. [3][4][5] Tremors, in particular when the frequency is high, can sometimes look like repetitive jerk-like movements and, oppositely, rhythmic myoclonic jerks can be misconstrued as tremor. 3 Startle syndrome commonly

Objective: To identify pre-operative clinical and computerized spiral analysis characteristics that may help ascertain which patients with Essential Tremor (ET) will exhibit ‘early tolerance’ to ventral intermediate nucleus of thalamus (Vim) deep brain stimulation (DBS). Methods: Identification of comparative characteristics of defined cases of ‘early tolerance’ versus patients with sustained satisfactory response treated with Vim DBS surgery for medically-refractory ET, based on retrospective chart review by a clinician blinded to the findings of computerized spiral analysis. Results: Statistically significant differences in two spiral analysis indices, SWVI and DoS, were found in the dominant upper limbs of patients who developed ‘early tolerance’, whereas the clinical characteristics were not significantly different. Conclusion: Objective measurements of upper limb kinematics using graphonomic tests like spiral analysis should be considered in the pre-operative evaluation for DBS, especially in the setting of moderate-severe predominantly action and proximal postural tremors. Significance: Ours is the first investigation looking into the pre-operative clinical and objective physiologic characteristics of the patients who develop ‘early tolerance’ to Vim DBS for the treatment of essential tremor. The study has significant implications for pre-operative evaluation and potential surgical target selection for the treatment of tremors.

Background: Many different oligosynaptic reflexes are known to originate in the lower brainstem which share phenomenological and neurophysiological similarities. Objective: To evaluate and discuss the differences and aberrancies among these reflexes, which are hard to discern clinically using neurophysiological investigations with the help of a case report. Methods: We describe the clinical and neurophysiological assessment of a young man who had a childhood history of opsoclonus-myoclonus syndrome with residual mild ataxia and myoclonic jerks in the distal extremities presenting with subacute onset total body jerks sensitive to sound and touch (in a limited dermatomal distribution), refractory to medications. Results: Based on clinical characteristics and insights gained from neurophysiological testing we could identify a novel reflex of caudal brainstem origin.

Highlights DTI study reveals brain-wide differences between SCA7 patients and controls. DTI dual-compartment model controls for increased CSF-like free water in patients. Tensor-based deformations show SCA7 tissue loss extends beyond cerebellum. Focal atrophy, but global microstructural abnormalities were observed in SCA7.

HighlightsMirror movements may mimic the phenomenon of ‘entrainment’ and can masquerade as functional tremors.Objective physiology and refinement of the current clinical and physiologic tremor evaluation techniques can help reduce misdiagnosis of functional tremor and help identify an underlying organic tremor etiology.Organic tremors may be an underrecognized co-morbidity in patients with diagnosed functional tremor.